March 23, 1922] 



NA TURE 



387 



Research Items, 



The Bull Acrobats at Knossus. — In the Journal 

 of Hellenic Studies (vol. xli. part 2) Sir Arthur Evans 

 describes a remarkable bronze group from Knossus 

 in Crete, representing an acrobat jumping over a 

 galloping bull in the arena. The high action and 

 skilful modelling of this animal are altogether unique 

 among the relics of Minoan metallurgic craft, and 

 for vigour and beauty this far exceeds two repre- 

 sentations of such feats discovered by Schliemann 

 and others. The full stretch of the bull's legs con- 

 forms to what is known as the " flying gallop " 

 scheme, and the small figure of the acrobat, apart 

 from the conventional attenuation of the waist, is 

 finely executed, and even his features, though ab- 

 normally diminutive and incompletely brought out 

 by the casting, with the sinewy development of 

 form, due to athletic training, are well indicated. 

 In other examples of feats of this kind the performer 

 is usually a girl, but there can be no doubt that this 

 figure is a male. In a representation of the same 

 class on the bull rhyton it is clear that at the epoch 

 to which it belongs, that is, about 2000 B.C., the long- 

 homed Urus breed of cattle had been already intro- 

 duced into Crete. The earlier indigenous variety, a 

 form of shorthorn. Bos Creticus of Boyd Dawkins, 

 was not well adapted for such a form of sport. 



The PALiEOHTHic Age in India. — The discovery 

 of stone implements in India began with an implement 

 found by Mr. Le Mesurier in 1861, and since that 

 time many specimens have been found. But only 

 two cases are known in India where stone implements 

 have been found associated with the remains of 

 extinct animals, in the Nerbudda and Godavari 

 valleys, and further evidence of their occurrence in 

 strata, the date of which can be established, is much 

 to be desired. In the March issue of Man Mr. T. H. 

 Vines reports the discovery of flint workshops in 

 hills overhanging the North Indus valley! These 

 consist of cores and broken chips, with a yellowish- 

 brown fabrication and lustre. In the ravines of 

 these hills flint knives and other tools of a white 

 or whitish colour are found in considerable numbers. 

 Mr. Vines suggests that the strata in which these 

 implements are found correspond with the area in 

 Egypt where implements of the same type have been 

 discovered by Prof. Seligman (Journal Royal Anthro- 

 pological Institute, vol. li. p. 115). The area to 

 which Mr. Vines refers well deserves examination, 

 as its geological character may form, the basis of 

 fixing an approximate age for manufacture of these 

 implements. 



Man in the Pacific. — At the meeting of the 

 British Association held in Australia in 19 14 the 

 desirability of fuller knowledge of the Pacific was 

 advocated. In response to this appeal the Legis- 

 lature of Hawaii appropriated funds to be used by 

 the Pan-Pacific Union in defraying the cost of a Pan- 

 Pacific Commercial and Educational Congress to be 

 held at Honolulu in 1920. The Bernice P. Bishop 

 Museum has now issued, as No. 7, Part I., of its 

 publications, a full report of the Proceedings of the 

 Congress, which are of peculiar interest. The papers 

 now published are devoted to the question of Race 

 Relations. In a valuable paper on " Man in the 

 icific," Dr. Clark Wissler remarked on the need 

 1 such investigations as " the old Polynesian is 

 passing the last mile-post of his career." " First, 

 we need a geological survey of the several island 

 trroups ; for the backbone of man's chronology is 

 ological chronology. Further, we need data upon 

 o fauna and flora of the respective islands. It is 

 liie reaUsation of this inter-relation of problems 



NO. 2734, VOL. 109] 



that underlies the conception of this congress and 

 is its only excuse for being. You tell us the history — 

 a relative chronology — of such plants as taro, bread- 

 fruit, the paper mulberry, etc., and the story of such 

 mammals as the pig and dog, and of the chicken, in 

 the islands of the Pacific, and we will soon fill in the 

 gaps in the chronological scheme for the Polynesians." 



The American Indians' Knowledge of the 

 Mastodon. — In Natural History, the Journal of the 

 American Museum of Natural History (vol. xxi. 

 No. 6), Mr. J. L. B. Taylor, under the heading : " Did 

 the Indian know th3 Mastodon ? " describes a bone 

 bearing an incised elephant-like figure, found in the 

 Jacobs Cavern, Ozark Country, near Pineville, 

 Missouri. Dr. Clark Wissler, who has examined this 

 bone, regards the work as what might have been 

 expected from the hand of an American native ; 

 three attempts to represent living forms, apparently 

 by the same artist, are identified — " Two have the 

 distinctive lines of elk and deer, while the lines of 

 the third characterise elephant kind, and this favours 

 the interpretation that an elephant, mastodon, or 

 mammoth was intended. At once the objection will 

 be raised that the bone is recent. Though the 

 mastodon and the mammoth are characteristic of 

 Pleistocene time, it is not known when they became 

 extinct : for all that is known to the contrary these 

 great mammals may have held out within 3000 years 

 ago. . . . No one in authority seems now prepared 

 to deny that man was in America 3000 years ago." 

 Dr. Wissler regards this discovery in Jacobs Cavern 

 as of great importance ; "it is to be hoped that 

 at last we are on the trail of early man in America." 



Behaviour of Stomata. — In a significant paper 

 on the behaviour of stomata (Carnegie Institution 

 of Washington, Publ. No. 314) Mr. J. V. G. Loft- 

 field has made important additions to our knowledge 

 of the action of stomata in relation to the environ- 

 mental and physiological conditions of the plant. 

 He used the method of fixing strips of the epidermis 

 in alcohol, supplemented by direct microscopic 

 observation of the living, attached leaf. Many of 

 the observations were continued every hour through- 

 out the day and night, microphotographs showing 

 the condition of the stomata on the upper and lower 

 epidermis of leaves being ingeniously arranged in 

 circles for comparison with the corresponding con- 

 tinuous circular records of light, temperature and 

 humidity. Many plants were studied under different 

 climatic conditions, and it was found that while 

 illumination affects the action of stomata, as has 

 long been known, yet weather conditions also control 

 the size of the openings, and with varying water 

 supply the stomata may change their behaviour 

 from day to day. Some of the movements were 

 quite rapid, from fully open to closed in less than an 

 hour. Low morning temperatures caused the stomata 

 to open very gradually, and even moonlight affected 

 the size of aperture. The great majority of the 

 stomata on a leaf behaved alike, but about 2 per cent, 

 were functionless and 3 per cent, superfunctional, 

 opening to twice the normal maximum. The plants 

 studied fell into three groups. In cereals the stomata 

 are very sensitive and never open at night. In 

 another group, as conditions become less favourable 

 the stomata open at night and close for a time about 

 midday. In the potato and other plants the stomata 

 are normally open at night and close only under 

 conditions of high evaporation or low water-content. 

 Light induces the opening of stomata by causing 

 the conversion of starch in the guard-cells into sugar 

 and so increasing their osmotic pressure. This work 



